• Journal of Plant Biotechnology
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• v.7 no.1
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• pp.1-15
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• 2005

Salinity is one of the major limiting factors for agricultural productivity. In plants, accumulation of osmolytes plays a pivotal role in abiotic stress tolerance. Likewise, exclusion or compartmentation of $Na^+$ ions into vacuoles provides an efficient mechanism to avert deleterious effects of $Na^+$ in the cytosol. Both vacuolar and plasma membrane sodium transporters and $H^+-ATPases$ can provide the necessary ion homeostasis. A variety of crop plants were engineered with respect to the synthesis of osmoprotectants and ion-compartmentation, but there are other cellular pathways involved in the salinity responses that are still not completely explored. Genomics approaches are increasingly used to identify genes and pathway changes involved in salt-tolerance. The new knowledge may be used via guided genetic engineering of multiple genes to create crop plants with significantly increased productivity in saline soils. This review surveys how plants deal with high salt conditions and how salt tolerance can be improved by transgenic approaches.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.202-202
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• 2017

Global climate change resulted in unwarranted change in global temperature and caused heat and cold stress, which are consider major threat to agriculture productivity around the world. The use of plant growth-promoting microbes is an eco-friendly strategy to counteract such stresses and confer tolerance to the plants. In current study, previously isolated endophytic fungi Preussia sp. BSL-10 has been found to produce phytohormones such as IAA and GA and as such, endophyte Preussia sp. BSL-10 found to induced tolerance against heat and cold stress. The results showed that under both heat and cold stress the plant growth parameter such as shoot, root length, shoot fresh weight and root fresh weight is higher in Preussia sp. BSL-10 treated plants as compare to free Preussia sp. BSL-10 control plants. In addition, the stress-sensitive endogenous ABA levels were significantly increased in Preussia sp. BSL-10 host plant. The current result suggest that the phytohormone-producing endophyte Preussia sp. BSL-10 can increase plant resistance toheat and cold stress, in turn improving agricultural productivity.

• Journal of Plant Biotechnology
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• v.4 no.2
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• pp.53-58
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• 2002

Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, 50-80% of the maximum potential yield is lost by these "environmental or abiotic stresses", which is approximately ten times higher than the loss by biotic stresses. Thus, improving stress-tolerance of crop plants is an important way to improve agricultural productivity, In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.n factors.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.3
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• pp.179-186
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• 1989

According to the results from the experiments of selecting a suitable variety of forage rape and comparing productivity and nutrient quality between forage rape and oil seed rape, Velox appeared to be the most suitable variety in terms of productivity and nutrient quality at the southern area of Korea among the varieties used in the experiments. Consequently, Velox was grown under two different cultural methods, individual culture and population culture, and productivity and variation of nutrient quality during the growth period were observed and compared between the cultural methods. The results from the experiment are summarized as follows: 1. Although variations were great in plant fresh weight and plant dry matter weight among plants, individual culture showed significantly higher value in these characters at the 1 % level than population culture. Plant fresh weight and plant dry matter weight were largely dependent upon the amount of branches in case of individual culture. However, in population culture, they were equally dependent upon the amount of branches and main stem. There was no significant difference in dry matter percentage between cultural methods, and main stem showed highest dry matter percentage. 2. Content of crude protein was decreasing gradually as plants continued to grow. Individual culture showed higher content of crude protein than population culture from 90 to 120 days after sowing but vice versa from 180 days after sowing to flowering stage. Contents of fiber such as NDF, ADF, cellulose and lignin was low at the early stage of growth. It was increasing gradually as plants grew older and at the latter stage of growth plants under individual culture showed higher values in contents of fiber. 3. In vitro dry matter digestibility (IVDMD) of both stems and leaves was decreasing gradually as plants grew older. Plants under individual culture showed higher IVDMD of stems than plants under population culture, but no significant difference in IVDMD of leaves was observed between cultural methods.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.12-12
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• 2017

Genetic improvement in potato can be carried out through several approaches, as sexual crosses, somatic hybridization, mutation and genetic engineering. Although the approach is different, but the goal is the same, to get a superior cultivar. Mutation and genetic engineering are very interesting methods for genetic improvement of potato plants. Mutation by gamma-ray irradiation have been performed to get some new potato cultivars which are more resistant to disease and have higher productivity. We have carried out a mutation of some potato cultivars and obtained some excellent clones to be potentially released as new superior cultivars. By the mutation method, we have released one potato cultivar for the French fries industry, and we registered one cultivar of potato for chips, and two cultivar for vegetable potatoes. Actually we are doing multi-location trial for three clones to be released as new cultivars. Through genetic engineering, several genes have been introduced into the potato plant, and we obtained several clones of transgenic potato plants. Transgenic potato plants containing FBPase gene encoding for fructose bisphosphatase, have a higher rate of photosynthesis and higher tuber productivity than non-transgenic plants. This result suggests that FBPase plays an important role in increasing the rate of photosynthesis and potato tuber productivity. Some transgenic potatoes containing the Hd3a gene are currently being evaluated for their productivity. Over expression of the Hd3a gene is expected to increase tuber productivity and induce flowering in potatoes. Transgenic potato plants containing MmPMA gene encoding for plasma membrane ATPse are more tolerant to low pH than non-transgenic plants, indicating that plasma membrane ATPase plays an important role in the potato plant tolerance to low pH stress. Transgenic potato plants containing c-lysozyme genes, are highly tolerant of bacterial wilt diseases caused by Ralstonia solanacearum and bacterial soft rot disease caused by Pectobacterium carotovorum. Expression of c-lyzozyme gene plays an important role in increasing the resistance of potato plants to bacterial diseases.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.175-195
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• 1997

The learning curve has an important effect the growth of corporation. But, in Korea, the study and inference on the learning rate of each industry are unprepared, and so, Korean industires have difficult in productivity and cost. At this point, this study infers the learning rate of the oil industries and investigates the productivity and growth of them. In conclusion, this study presents the direction of the oil industries' development. With the intention of this objects, this study seizes the status which is concerned the total quantity, the operating rate, the plant capacity, the indicators concerning productivity, the investment of R & D and the scales, and then, infers and verifies the relevancy in connection with the learning rate. In the oil industry, the average rate of learning is 65.96% from 1982 to 1994 which the total quantity and the average operation time are used to infer the rate. To observe the low rate within a same period of time, this study takes the consequences that the learning rate is almost indentical with them each year. This steady state is caused by a difference between the employee and the decision maker about the acquirement and assimiliated of technology. When the high-quality technologies posses the environment to applicate in the scene of labor with them, this technology applies to the productivities. As the learning rate increases, the productivity has more effectiveness. The result of analysis about the effectiveness of the learning rate follows that the R & D unfoldes to exist and does not contribute to the growth of the oil industry. To analyze the variables of the growth, such as the learning rate, the investement of R & D, the operating rate and the gross value added to property, plant and equipment, the model is established and examined. The business strategy in the oil industry must be developed to achive the internal growth as well as the external.

• Food Science and Preservation
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• v.7 no.1
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• pp.99-102
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• 2000

Comparing and analysing the productivity and the main ingredients of persimmon leaves by cultivars were conducted to improve the quality and productivity of the per-simmon leaf tea. As a result of the survey, Dungsi was decidedly good in growth co-ndition of survival rate, stem diameter and the number of shoots etc. Also , DUngsi had the highest leaf productivity of 567 leaves and the leaf weight of 1.98 kg per one plant after three years of planting . On accounts of productivity, ingredient analysis and panel test etc. we collectively through that Dungsi was the best cutltivar for the persimmon leaf tea.

• Animal Bioscience
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• v.36 no.4
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• pp.540-554
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• 2023

Heat stress is a major challenge to animal production in tropical and subtropical climates. Rabbits suffer from heat stress more than farm animals because they have few sweat glands, and their bodies are covered with thick fur. Intensive farming relies on antibiotics as antimicrobials or growth promoters to increase animals' productivity and health. However, the European Union and many countries have banned or restricted the use of antibiotics in animal feed for human health concerns. Several studies have found that replacing antibiotics in rabbit feed with natural plants or feed additives increases productivity and improves immune capacity, especially under heat stress conditions. Growth performance, immune response, gut microflora, and carcass yield may be increased in rabbits fed a diet supplemented with some natural plants and/or propolis. In this review article, we discuss and summarize the effects of some herbs and plant extracts as alternative feed additives on rabbit productivity, especially for those raised under hot ambient temperatures.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.582-592
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• 2012

Microorganisms present in the rhizosphere soil plays a vital role in improving the plant growth and soil fertility. Many kinds of fertilizers including chemical and organic has been approached to improve the productivity. Though some of them showed significant improvement in yield, they failed to maintain the soil properties. Rather they negatively affected soil eventually, the land became unsuitable for agricultural. To overcome these problems, microorganisms have been used as effective alternative. For past few decades, plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) have been used as effective inoculants to enhance the plant growth and productivity. PGPR improves the plant growth and helps the plant to withstand biotic and abiotic stresses. AM fungi are known to colonize roots of plants and they increase the plant nutrient uptake. Spore associated bacteria (SAB) are attached to spore wall or hyphae and known to increase the AMF germination and root colonization but their mechanism of interaction is poorly known. Better understanding the interactions among AMF, SAB and PGPR are necessary to enhance the quality of inoculants as a biofertilizers. In this paper, current knowledge about the interactions between fungi and bacteria are reviewed and discussed about AMF spore associated bacteria.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.1
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• pp.20-25
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• 1989

This experiment was carried out in order to know the decreasing causes of plant density and its relations with pasture productivity by the times of established pasture. The results were summarized as follows, 1. The yield components of dead plant can be used to estimate the changes of pasture productivity by the times of established pasture. 2 . The number of dead plants(PD) showed a quadraticalrelation with mean dry weight of dead plant $W/pl.)$ by the times of established pasture. 3. Relationship between relative number of tillers per dead plant to mean number of tillers of adjacent plants (RNT) and relative ratio of number of tillers per dead plant to number of tillers of plants in the 1st cutting (RNDT) showed highly positive significant correlation in 1 and 3 years old pasture. 4. Less than 100 of RNT were 79.5 %, 71.4 % and 100 % of dead plants in 1, 3 and 5, and 7 years old pasture, respectively. 5. Not exceeding values of RNDT to MRRNT were 89.7 %, 71.4 % and 100 % of dead plants in 1, 3 and 5, and 7 years old pasture. 6 . The values of 79.5 %, 57.2 % and 100 % of dead plants in 1, 3 and 5, and 7 years old pasture were not exceeding to MRRNT and less than 100 of RNT. 7. From the results described above, it was discussed that the relative number of tillers per dead plant(RNT) should be described not absolute deaeasing causes of plant density in 1 and 3 yars old pasture. But, the total number of dead plants in 5 and 7 years old pasture were absolutely influenced by RNT and MRRNT.